<template>
<div>
    <router-link tag="div" to="/" class="header-abs" v-show="showAbs">
      <div class="iconfont header-abs-back">&#xe624;</div>
    </router-link>
    <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
      <router-link to="/">
            <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
    <div class="content"></div>
</div>
</template>

<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = { opacity }
        this.showAbs = false
      }else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll',this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll',this.handleScroll)
  }
}
</script>

<style lang="stylus" scoped>
@import '~styles/varibles.styl'
.content{
  height: 50rem;
}
.header-abs{
  position: absolute
  left: .2rem
  top: .2rem
  width: .8rem
  height: .8rem
  line-height: .8rem
  border-radius: .4rem
  text-align: center
  background: rgba(0, 0, 0, .8)
}
.header-abs-back{
  color: #fff
  font-size: .4rem
}
.header-fixed{
  z-index: 2;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: $headerHeight;
  line-height: $headerHeight;
  text-align: center;
  color: #fff;
  background: $bgColor;
  font-size: .32rem;
}
.header-fixed-back{
  position: absolute;
  top: 0;
  left: 0;
  width: .64rem;
  text-align: center;
  font-size: .4rem;
  color: #fff;
}
</style>